Combined utility of CD177, P53, CD105 and c-kit immunohistochemical stains improves the detection of myelodysplastic syndrome.

The diagnosis of myelodysplastic syndrome (MDS) relies primarily on identifying peripheral blood cytopenia and morphologic dysplasia as well as detecting cytogenetic aberrations in a subset of patients. Accumulating data points to the importance of examining certain immunophenotypic changes characteristic of MDS, most of which are tested by flow cytometry. The role of immunohistochemistry in the diagnostic workup of MDS is less known. In this study, we used immunohistochemistry to survey the expression patterns of CD177, P53, CD105 and c- kit in a cohort of MDS bone marrow specimens (n = 57) and compared the results with a control group of patients who had cytopenia for other benign conditions (n = 49). MDS cases showed significant higher rates of: CD177-loss (13/57, 23% vs 1/49, 2%; P = .0016), P53 overexpression (8/57, 14% vs none; P = .005) and the presence of clusters of CD105-positive cells (6/57, 11% vs none; P = .021). Increased c-kit-positive cells was more common in MDS patients, but not statistically significant (17/57, 30% vs 8/49, 16%; P = .102). On multivariate analysis, only loss of CD177 expression was significantly higher in MDS group (P = .014). These findings suggest that a panel of immunohistochemical stains could serve as an adjunct tool in investigating unexplained cytopenias and warrant further comparative studies with flow cytometry.

Paediatric essential thrombocythaemia: clinical and molecular features, diagnosis and treatment.

The incidence of essential thrombocythaemia (ET) in children (age ≤18 years) is extremely low. The natural course of the disorder in children has not been clarified. The rarity of patients and the variability of tested parameters make it difficult to draw any definitive conclusion in pathogenesis and diagnosis of paediatric ET. What makes the onset of thrombocytosis earlier in children is still uncertain. A diagnostic algorithm for paediatric ET has not been established, and current risk stratification used to guide therapeutic decisions in adults has not been validated in children. Vascular complications and transformation to myelofibrosis and leukaemia in this special entity have been reported, suggesting that ET in children is not an entirely benign disease. The crucial question is how to identify patients who are at high risk of complications and need treatment. There are insufficient data to recommend a specific agent in children. The purpose of this review is to outline the most recent progress in paediatric ET and to help with understanding the clinical course, molecular features, diagnosis and treatment strategies in this special group.

Gene expression analysis of a Helicobacter pylori-infected and high-salt diet-treated mouse gastric tumor model: identification of CD177 as a novel prognostic factor in patients with gastric cancer.

BACKGROUND: Helicobacter pylori (H. pylori) infection and excessive salt intake are known as important risk factors for stomach cancer in humans. However, interactions of these two factors with gene expression profiles during gastric carcinogenesis remain unclear. In the present study, we investigated the global gene expression associated with stomach carcinogenesis and prognosis of human gastric cancer using a mouse model. METHODS: To find candidate genes involved in stomach carcinogenesis, we firstly constructed a carcinogen-induced mouse gastric tumor model combined with H. pylori infection and high-salt diet. C57BL/6J mice were given N-methyl-N-nitrosourea in their drinking water and sacrificed after 40 weeks. Animals of a combination group were inoculated with H. pylori and fed a high-salt diet. Gene expression profiles in glandular stomach of the mice were investigated by oligonucleotide microarray. Second, we examined an availability of the candidate gene as prognostic factor for human patients. Immunohistochemical analysis of CD177, one of the up-regulated genes, was performed in human advanced gastric cancer specimens to evaluate the association with prognosis. RESULTS: The multiplicity of gastric tumor in carcinogen-treated mice was significantly increased by combination of H. pylori infection and high-salt diet. In the microarray analysis, 35 and 31 more than two-fold up-regulated and down-regulated genes, respectively, were detected in the H. pylori-infection and high-salt diet combined group compared with the other groups. Quantitative RT-PCR confirmed significant over-expression of two candidate genes including Cd177 and Reg3g. On immunohistochemical analysis of CD177 in human advanced gastric cancer specimens, over-expression was evident in 33 (60.0%) of 55 cases, significantly correlating with a favorable prognosis (P = 0.0294). Multivariate analysis including clinicopathological factors as covariates revealed high expression of CD177 to be an independent prognostic factor for overall survival. CONCLUSIONS: These results suggest that our mouse model combined with H. pylori infection and high-salt diet is useful for gene expression profiling in gastric carcinogenesis, providing evidence that CD177 is a novel prognostic factor for stomach cancer. This is the first report showing a prognostic correlation between CD177 expression and solid tumor behavior.

Granulocyte antibody screening: evaluation of a bead-based assay in comparison with classical methods.

BACKGROUND: Granulocyte antibodies have been implicated in allo- and autoimmune neutropenia and in transfusion reactions. STUDY DESIGN AND METHODS: Fifty-one sera from suspected alloimmune neutropenia or transfusion-related acute lung injury (TRALI) and 40 sera from suspected autoimmune neutropenia were tested for granulocyte antibodies using LABScreen MULTI (One Lambda, Inc.), compared with classical tests (flow cytometry [FC] and granulocyte agglutination [GAT] followed by monoclonal antibody-specific immobilization of granulocyte antigens [MAIGA]). RESULTS: In alloimmune situations, 48 sera were concordant (94%), two sera positive for HNA with LABScreen MULTI were negative by FC/GAT and/or MAIGA, and one serum sample negative for HNA with LABScreen MULTI was positive by classical tests. In autoimmune neutropenia, 30 sera were concordant (75%), four sera positive for HNA with LABScreen MULTI were negative by FC/GAT and/or MAIGA, and six sera negative for HNA with LABScreen MULTI were positive by FC/GAT and/or MAIGA. For detection of autoantibodies, the LABScreen MULTI was less concordant. However, with the exception of one case, the discrepancies were observed in sera that did not show a clear specificity. CONCLUSIONS: LABScreen MULTI correlated well with our classical methods for HNA-1 and HNA-2a antibody screening. It can be used for screening blood donors or patients suspected of TRALI, but GAT is still needed for HNA-3a antibody screening.

Human neutrophil alloantigen-1a, -1b, -2, -3a and -4a frequencies in Brazilians.

Human neutrophil reactive antibodies may cause clinical disorders such as transfusion-related acute lung injury, febrile transfusion reactions, alloimmune neonatal neutropenia, immune neutropenia after stem cell transplantation, refractoriness to granulocyte transfusion, drug-induced neutropenia and autoimmune neutropenia. Using the granulocyte immunofluorescence test by flow cytometry, the phenotypic frequencies of the human neutrophil alloantigens (HNA)-1a, -1b, -2, -3a and -4a were determined in 100 healthy Brazilian persons. Neutrophils were separated from blood samples by sedimentation, centrifugated and incubated with HNA-specific alloantibody plus fluorescein isothiocyanate-labeled F(ab')(2) fragments of anti-human IgG. The results showed that the phenotype frequencies of HNA-1a, -1b, -2a, -3a and -4a were 65%, 83%, 97%, 95% and 94%, respectively. We detected that neutrophils from 17% of Brazilians typed positive only with anti-HNA-1a (HNA-1a/a), 35% only with anti-HNA-1b (HNA-1b/b) and 48% reacted with both antibodies (HNA-1a/b). The frequencies found for HNA-1a and -1b were quite similar to that reported among Africans and American-Africans, but different from those found in Japanese and Chinese. In addition, our data showed that the frequencies of HNA-2, -3a and -4a in Brazilians were comparable with those observed in Caucasians. The determination of HNAs frequencies among populations with distinct racial backgrounds is important not only for anthropological reasons, but also for neonatal typing in suspected cases of alloimmune neutropenia or when patients are severely neutropenic.

Allospecific CD154+ T cells identify rejection-prone recipients after pediatric small-bowel transplantation.

BACKGROUND: Up to 70% of children with small bowel transplantation (SBTx) experience acute cellular rejection (ACR). Allospecific CD154+ T cells predict liver ACR in children in a novel, 16-hour mixed leukocyte response (MLR) assay, but remain untested in SBTx. METHODS: The expression of CD154 was measured in 4 subsets-naive (N) and memory (M) CD154+ T-helper (Th) and T-cytotoxic (Tc) cells (ie, CD154+ ThN, CD154+ ThM, CD154+ TcN, and CD154+ TcM, respectively)-in the MLR of single blood samples obtained from 32 children with SBTx within 60 days of SBTx biopsy. Children showing ACR in these biopsies were termed Rejectors. The ratio of donor-induced to third-party-induced CD154+ T cells was called the immunoreactivity index (IR). We hypothesized that IR >1 denoted increased donor-specific alloreactivity and increased risk of rejection; in contrast, IR <1 implied decreased risk. CD154 expression was correlated with the expression of CTLA4, a negative T-cell costimulator that antagonizes and is inversely related to CD154 (n = 18). RESULTS: Rejectors showed significantly greater numbers of donor-specific CD154+ T-cell subsets. Logistic regression analysis and leave-one-out cross validation followed by receiver operating characteristic analysis showed that, among the 4 subsets, IR > or =1.23 for CD154+ TcM identified Rejectors with a sensitivity and specificity of 93% and 88%. Also, a significant negative correlation was observed between CD154 expression and CTLA4 expression in allospecific Tc (Spearman's rho = -0.616, P = .006) but not in Th. CONCLUSION: Allospecific CD154+ TcM identify rejection-prone children with SBTx.

Allergic airway hyperreactivity increases the risk for corneal allograft rejection.

Corneal allografts transplanted into hosts with allergic conjunctivitis experience an increased incidence and swifter tempo of immune rejection compared to corneal allografts transplanted to nonallergic hosts. Previous findings suggested that increased risk for rejection was not a local effect produced by an inflamed eye, but was due to perturbation of the systemic immune responses to alloantigens on the corneal allograft. We tested the hypothesis that another allergic disease, airway hyperreactivity (AHR), would also increase the risk for corneal allograft rejection. Induction of AHR with either ovalbumin (OVA) or short ragweed (SRW) extract prior to keratoplasty resulted in a steep increase in the speed and incidence of corneal allograft rejection. Delayed-type hypersensitivity (DTH) responses to corneal alloantigens were closely associated with corneal allograft rejection. However, the deleterious effect of AHR on corneal allograft survival was not reflected in a heightened magnitude of allospecific DTH, cytotoxic T lymphocyte and lymphoproliferative responses to the alloantigens on the corneal allograft. Unlike Th2-based immediate hypersensitivity, CD8+ T-cell-based contact hypersensitivity to oxazolone did not increase the risk for corneal allograft rejection. Thus, Th2-based allergic diseases significantly reduce the immune privilege of the corneal allograft and represent important risk factors for consideration in the atopic patient.

Coexpression of CD177 and membrane proteinase 3 on neutrophils in antineutrophil cytoplasmic autoantibody-associated systemic vasculitis: anti-proteinase 3-mediated neutrophil activation is independent of the role of CD177-expressing neutrophils.

OBJECTIVE: Wegener's granulomatosis (WG) is strongly associated with antineutrophil cytoplasmic autoantibodies (ANCAs) directed against proteinase 3 (PR3). Recent studies have shown that membrane-bound PR3 (mPR3) is differentially expressed and colocalizes with CD177/NB1 on circulating neutrophils. We undertook this study to assess the differential expression of CD177 on neutrophils from patients with ANCA-associated systemic vasculitis (ASV) in comparison with patients with systemic lupus erythematosus (SLE), patients with rheumatoid arthritis (RA), and healthy individuals, and to investigate whether colocalization of mPR3 and CD177 affects anti-PR3-mediated neutrophil activation. METHODS: Expression of CD177 and mPR3 was analyzed by flow cytometry on isolated neutrophils from patients with ASV (n=53), those with SLE (n=30), those with RA (n=26), and healthy controls (n=31). Neutrophil activation mediated by anti-PR3 antibodies was assessed by measuring the oxidative burst with a dihydrorhodamine assay. RESULTS: Percentages of CD177-expressing neutrophils were significantly higher in patients with ASV and those with SLE than in healthy controls. In 3 healthy donors, CD177 expression was not detected. After priming with tumor necrosis factor alpha, neutrophils remained negative for CD177 while mPR3 expression was induced. Neutrophils from CD177-negative donors or CD177- neutrophils sorted from donors with bimodal expression were susceptible to anti-PR3-mediated oxidative burst. Variation in the extent of anti-PR3-mediated neutrophil activation among different donors occurred independent of the percentage of CD177-expressing neutrophils. CONCLUSION: Membrane expression of CD177 on circulating neutrophils is increased in patients with ASV and in those with SLE, but not in RA patients. However, primed neutrophils from CD177-negative individuals also express mPR3 and are susceptible to anti-PR3-mediated oxidative burst, suggesting that recruitment of CD177-independent mPR3 is involved in anti-PR3-induced neutrophil activation.

Monitoring neutrophil engraftment in allogeneic stem cell transplantation by flow cytometric analysis of neutrophil-specific antigens NA1 and NA2.

Neutrophil-specific antigen (NA) expression on neutrophils was analysed in 18 Japanese children before and after allogeneic stem cell transplantation (allo-SCT) with myeloablative regimen. Donor-recipient NA-incompatibility was present in one of eight NA1/NA2 heterozygous patients and eight of 10 NA1/NA1 or NA2/NA2 homozygous patients. After allo-SCTs from NA-incompatible donors, a neutrophil recipient-to-donor conversion was confirmed in all cases. Conversion to donor NA type was complete before the absolute neutrophil count reached 0.1 x 10(9)/l. These observations indicate that flow cytometric analysis of NA antigens is a simple and useful method for monitoring neutrophil engraftment in NA-incompatible allo-SCT.

Comparison of two immunomagnetic separation technologies to deplete T cells from human blood samples.

The objective of this study was to compare the performance of two immunomagnetic separation technologies to deplete T cells from buffy coats of human blood. Specifically, two versions of the commercial MACS(R) Technology: MiniMACS and SuperMACS, and a prototype, flow-through system, the QMS, were evaluated. Peripheral blood mononuclear leukocytes (PBL) were isolated from buffy coats and an immunomagnetic separation of CD3(+) cells was conducted using company and optimized labeling protocols. To mimic peripheral blood containing bone marrow purged hematopoietic stem cells, HSC, CD34 expressing-cells (KG1a) were spiked into PBL prior to T-cell depletion once optimized depletion conditions were determined. Once the labeling protocol was optimized, the MiniMACS system performed well by producing a highly enriched CD3(+) fraction, and a respectable level of depletion of T cells and recovery of KG1a cells in the depleted fraction; an average log(10) depletion of T cells of 2.88 +/- 0.17 and an average recovery of the KG1a cells of 60.8 +/- 5.94% (n = 14). The performance of the SuperMACS system was very similar with an average log(10) depletion of T cells of 2.89 +/- 0.22 and an average recovery of KG1a of 63.1 +/- 8.55% (n = 10). In contrast, the QMS system produced an average log(10) depletion of T cells of 3.98 +/- 0.33 (n = 16) with a corresponding average recovery of 57.9 +/- 16.6% of the spiked CD34+ cells. The aforementioned QMS performance values were obtained using sorting speeds ranging from 2.5 x 10(4) to 1.7 x 10(5) cells per second. It is suggested that the lack of a 100% recovery of the unlabeled KG1a cells is the result of a previously reported "drafting" phenomena which pulls unlabeled cells in the direction of the magnetically labeled cells thereby resulting in loss of the unlabeled cells.

Zidovudine plus sulfamethoxazole-trimethoprim adversely affects B lymphocyte maturation in bone marrow of normal mice.

Sulfamethoxazole-trimethoprim and zidovudine (AZT), drugs used often in combination in patients infected with HIV, were investigated for their effects on B cell development in a mouse model. BALB/c mice were randomized to receive oral doses of AZT, sulfamethoxazole-trimethoprim, or the combination via oral gavage for up to 28 days. Immune cell populations in the spleen, lung, and peripheral blood were examined, and toxicity to B lineage subtypes in the bone marrow was investigated by phenotypic analysis via flow cytometry. Pre-pro-B, pro-B, early pre-B, and late pre-B cells were assayed for apoptosis and analyzed for cell cycle profile. Total as well as B cell splenic and bone marrow cellularities were significantly decreased by using the drugs concomitantly, while B cell populations in the lungs and percentage in the peripheral blood were not affected. Combination therapy caused significant increases in apoptosis in B cells and granulocytes in the bone marrow, with the late pre-B cell population being the most depleted. The proliferative expansion and differentiation of early pre-B cells (B220+/CD43+/BP-1+/HSA+) to the late pre-B cell (B220+/CD43-/IgM-) stage was blocked, with early pre-B cells accumulating in the proliferative phases of the cell cycle. This apoptosis increase is likely due to elevated blood sulfamethoxazole concentrations that were observed in mice also receiving AZT. Concurrent sub-chronic administration of AZT and sulfamethoxazole-trimethoprim adversely affected B lymphocyte development in mouse bone marrow.

Neutrophil polycythemia rubra vera-1 expression in classic and atypical myeloproliferative disorders and laboratory correlates.

The current study of 153 subjects with both classic and atypical myeloproliferative disorders suggests that neutrophil polycythemia rubra vera-1 (PRV-1) over-expression is a non-specific feature of clonal myeloproliferation that displays significant correlation with leukocyte alkaline phosphatase score. These observations undermine the utility of the PRV-1 assay as a diagnostic test of additional value.

Cross-recognition of human alloantigen by cytomegalovirus glycoprotein-specific CD4+ cytotoxic T lymphocytes: implications for graft-versus-host disease.

Presence of the HLA-DR7 allele in patients who receive transplants has been proposed as a risk factor for human cytomegalovirus (HCMV)-associated complications; however, the precise mechanism of this increased risk remains unresolved. Here we show that HLA-DR7-restricted HCMV-specific CD4(+) cytotoxic T lymphocytes (CTLs) can display an unusual dual specificity toward a glycoprotein-B (gB) epitope and the alloantigen HLA-DR4. However, no HLA-DR4-specific alloreactivity was observed when the gB-specific CTLs were generated from virus carriers expressing both HLA-DR7 and DR4 alleles. This most likely demonstrates the clonal inactivation of potentially self-reactive T cells in humans. Fine specificity analysis showed that gB-specific CTLs from HLA-DR7(+)/DR4(-) individuals displayed a distinct pattern of recognition when compared with CTLs from HLA-DR7(+)/DR4(+) individuals, presumably evading an area of the epitope that mimics a structure presented on HLA-DR4. These data illustrate a possible mechanism for the clinical association between HCMV and graft-versus-host disease.

Unexpected mortality in pediatric patients with postoperative Hirschsprung's disease.

Hirschsprung's disease is characterized by lower intestinal obstruction. In this retrospective study, we investigated the postoperative complications and the causes of death in pediatric patients with Hirschsprung's disease. Between January 1981 and June 1998, 147 patients with Hirschsprung's disease underwent surgical intervention (129 with both colostomy and Soave's pull-through procedures) at Mackay Hospital. Of 147 total patients, 83.67% had aganglionosis in the rectosigmoid, 5.44% had colon involvement, and 4.08% had total colon aganglionosis, documented pathologically after a Soave's pull-through procedure. Any post-pull-through patient who showed symptoms of fever, leukocytosis, diarrhea, and clinical sepsis was diagnosed with Hirschsprung's enterocolitis. Four patients died within 4.5 months of surgery, and one patient died more than 4 years after surgery; these five patients were positive for Thomsen (T-) antigen. One patient died soon after rectal irrigation was performed in preparation for the surgery. All five of these patients had sepsis clinically, and anaerobic sepsis was attributed as the main cause of their deaths. Of interest in these cases is the presence of T-antigen, a potentially useful marker for anaerobic bacterial infection that may not be well known to most pediatricians. We recommend (1) determining the presence of T-antigen in patients with recurrent Hirschsprung's enterocolitis, (2) administering empirical antibiotics with anti-anaerobic activity as soon as possible, and (3) irrigating the colon in those patients who develop sepsis after a pull-through procedure.

Instability of PRV-1 mRNA: a factor to be considered in PRV-1 quantification for the diagnosis of polycythemia vera.

High expression of PRV-1 mRNA in granulocytes has been proposed as a new diagnostic marker for polycythemia vera. We used real-time reverse transcription polymerase chain reaction (RT-PCR) to measure the levels of PRV-1 mRNA, GAPDH mRNA and 18S rRNA in granulocytes obtained from blood samples processed 2, 24 and 48 hours after collection and observed a significant decrease of PRV-1 levels after 24 and 48 hours. The instability of PRV-1 mRNA may affect the diagnostic value of the PRV-1 test in blood samples stored for extended periods.

Is MAGE-1 expression in metastatic malignant melanomas really helpful?

Melanoma antigen-encoding gene (MAGE-1) has been introduced as a sensitive immunohistochemical marker to aid in the diagnosis of malignant melanomas, in particular, those that are HMB-45 negative. Our goal was to determine the consistency of positive staining in melanomas on the basis of the usefulness of MAGE-1 in comparison with tyrosinase and MART-1. We studied 56 malignant melanomas using immunohistochemical markers to MAGE-1, tyrosinase, MART-1, HMB-45, and S-100. Six of 17 HMB-45-negative cases were strongly positive for MAGE-1 (35%), while 9 of 39 HMB-45-positive cases were positive for MAGE-1 (23%), overall, 27% positivity (n = 56). Tyrosinase and MART-1 were both strongly positive in 42 of 56 cases (75%). Fifty-two of 56 cases were strongly positive for S-100 (93%). We found MAGE-1 to be less sensitive than described in other studies, and overall, not very helpful, especially as a predictor of aggressive behavior. Although MAGE-1 expression has been considered as a target for immunomodulation therapy, our findings do not indicate consistent expression of this epitope in a majority of melanomas. S-100 protein, tyrosinase, and MART-1 immunomarkers were more frequently positive in our melanoma cases and appear to constitute a useful panel of markers to aid in the diagnosis of metastatic malignant melanomas, especially in patients with an unknown primary.

Improved detection of clinically significant host-reactive antigens prior to HLA-identical sibling peripheral blood stem cell transplantation using a dendritic cell-based helper T-lymphocyte precursor assay.

SUMMARY: Graft-versus-host disease (GVHD) due to host-reactive antigenic differences between HLA-identical pairs remains an important cause of morbidity and mortality after allogeneic transplantation. The helper T-lymphocyte precursor (HTLp) assay, using peripheral blood mononuclear cells (PBMCs), has been variably shown to detect such host-reactive differences. We assessed whether using dendritic cells (DCs) as the stimulator cells would improve the ability of the HTLp assay to detect these differences. We used PBMCs (standard HTLp assay) or monocyte-derived DCs (DC-HTLp assay) as the stimulator cells for 12 HLA-identical sibling pairs undergoing allogeneic peripheral blood stem cell transplantation. HTLp frequencies were greater by the DC-HTLp assay (median 1:77 712 vs 1:727 514; P=0.008). The standard HTLp assay did not predict for acute GVHD (P=0.42), whereas a trend was noted for the DC-HTLp assay (P=0.095). Of note, of seven patients developing moderately severe to severe acute GVHD, four had a significantly greater DC-HTLp frequency compared to the standard HTLp frequency, whereas all four patients who developed no to moderate acute GVHD had similar HTLp frequencies whether PBMCs or DCs were used as the stimulator cells. Although the small number of donor/recipient pairs assessed limits the strength of any conclusions, our study suggests that the DC-HTLp assay is better able to detect clinically significant host-reactive antigenic differences between HLA-identical siblings.

Strain- and blood group-dependent binding of Helicobacter pylori to human gastric MUC5AC glycoforms.

BACKGROUND & AIMS: In the stomach, Helicobacter pylori is found both in the mucus layer and adhering to the gastric epithelium. The aim of this study is to characterize the binding of H. pylori to human gastric mucins. METHODS: H. pylori strains that bind the Lewis(b) (Le(b)) structure (via the BabA adhesin) and/or sialylated structures, along with isogenic adhesion deletion mutants, were used to identify microbe-binding mucins. Gastric mucins from 5 healthy individuals, isolated by density-gradient centrifugation, were investigated for H. pylori binding at neutral pH using a microtiter-based technique. RESULTS: H. pylori strains that express the BabA adhesins were shown to bind to the MUC5AC mucin in individuals expressing the Le(b) antigen. Further fractionation with an ion-exchange chromatography revealed Le(b)-positive MUC5AC glycoforms that differed in their receptor properties for different H. pylori strains. None of the H. pylori strains studied bound to mucins from Le(b)-negative individuals. However, all strains bound to low-density, nonmucin, Le(b)-negative material on top of the gradients. CONCLUSIONS: Binding of H. pylori to human gastric MUC5AC isolated from healthy individuals is BabA dependent and mediated by the Le(b) structure presented by the mucin. However, the BabA adhesins demonstrate strain-dependent preference in binding to MUC5AC glycoforms substituted with Le(b), allowing for great interindividual variability in host-microbe interactions.

Large scale identification of human hepatocellular carcinoma-associated antigens by autoantibodies.

Autoantibodies are often detected in hepatocellular carcinoma (HCC), and these responses may represent recognition of tumor Ags that are associated with transformation events. The identities of these Ags, however, are less well known. Using serological analysis of recombinant cDNA expression libraries (SEREX) from four HCC patients, we identified 55 independent cDNA sequences potentially encoding HCC tumor Ags. Of these genes, 15 are novel. Two such proteins, HCA587 and HCA661, were predominantly detected in testis, but not in other normal tissues, except for a weak expression in normal pancreas. In addition to HCC, these two Ags can be found in cancers of other histological types. Therefore, they can be categorized as cancer-testis (CT) Ags. Two other Ags (HCA519 and HCA90) were highly overexpressed in HCC and also expressed in cancer cell lines of lung, prostate, and pancreas, but not in the respective normal tissues. Four other Ags were identified to be expressed in particular types of cancer cell lines (HCA520 in an ovarian cancer cell line, HCA59 and HCA67 in a colon cancer cell line, HCA58 in colon and ovarian cancer cell lines), but not in the normal tissue counterpart(s). In addition, abundant expression of complement inactivation factors was found in HCC. These results indicate a broad range expression of autoantigens in HCC patients. Our findings open an avenue for the study of autoantigens in the transformation, metastasis, and immune evasion in HCC.